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2002 Ford Taurus major vacuum leak

5K views 19 replies 4 participants last post by  Fitz8710 
#1 ·
So i have a 2002 ford Taurus with OHV 3.0 Vulcan. I have been chasing what seems to be a vacuum leak according to obd2 (15 to 20 LTFT on both banks at idle). When starting engine at ambient temperature the idle is erratic up and down from 500 to 900 rpms. The obd is telling me the vacuum is as low as 9 to 15 at idle. Whenever I hit the throttle in the engine bay i get a woosh coming from the intake (yes woosh is a technical term lol) . Well....lol I have been writing this on and off for the last few hours so please excuse the brokeness of this post. I just got back inside from running a smoke test on the vac system anddddd it seems that i have a leak behind the upper intake where the EGR is connected to the plasticon the upper intake. I will post my results today or tommorrow once i do the repair so hopefully this will help some people if they run into this problem.
I just got done doing lower intake gaskets and oil pan gaskets so im pretty much ready to set this car on fire... o_O
 
#3 ·
So heres an update. I just installed the egr Oring seal. Turns out the replacement was a round o ring instead of the flat seal OEM style (correct me if im wrong please). Never the less it fit well. Thank you for mentioning checking on it to make sure it did not slip. I made sure to press the oring into the shaft before i tightened the two bolts down. Still having the same problem. Low vacuum on cold start. Still getting the wooshing sound when pressing the throttle. Im really starting to think my plastic upper intake has a hairline fracture that seals when it heats up maybe? It seems like i hear it from the bottom side of the upper intake. I tried spraying it with carb spray while "wooshing" it but i really cant get at it to spray it.
 

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#5 ·
So i took off the vacuum dist valve and used 2 part 3m polyurethane glue along the seals of what im guessing are check valves. Went for a test run and vacuum seems a little better but my LTFT for both banks are still around 15 percent at idle ( damn near 0 to 2 percent while cruising)
Ill have to wait until morning to try a true cold start and see if the erratic cold idle went away. Im still thinking hairline crack or something wrong with upper manifold (oh Ford WHY PLASTIC....lol). Let me know what you all think... even if you think im crazy ?
 
#11 ·
Did the test. Found out the new egr gasket did not seal. So i used rtv. Did another smoke test after that dried and smoke is coming out of the seams of the egr disc itself. Its weird because i tested with a vacuum pump on the top nipple and it held vacuum at the egr. Guess its time for a new egr.
 
#13 ·
Figuring that the valve cover probably has nothing to do with my cold start (valve cover access to vacuum system is before the throttle plate and intake) i am back to possibly a bad upper intake. If i tap on it with a rubber mallet after i start it i can hear a slight woosh..
 
#14 ·
So i blocked off the hose going to the front valve cover from the accordion (before throttleplate) and i performed another smoke test. I had smoke coming out of the front cover still. Is it possible the front valve cover is tied in with the intake vacuum system?
 
#19 ·
Replaced valve cover gaskets. And put 6 new properly gapped spark plugs in. Still has a rough start. So i got the good ol stethoscope out and started searching for where the woosh noise after hitting the throttle is coming from. Seems like its coming from the egr tube seal on the upper intake. Maybe i did not seal it properly? I will find out after i take the upper intake off for the 9th time...lol
 
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